"That’s a great question and it is a great — it would be a great thing to do but because the Senate is controlled by Democrats we would never be able to get the Senate first to take up that action, because they simply don’t care what the American public thinks. They would protect him and they wouldn’t even bring it up," Cain said, citing the administration's position on the Defense of Marriage Act as an impeachable offense.

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More from his answer: "So the main stumbling block in terms of getting him impeached on a whole list of things such as trying to pass a health care mandate which is unconstitutional, ordering the Department of Justice to not enforce the Defense of Marriage Act — that’s an impeachable offense right there. The president is supposed to uphold the laws of this nation … and to tell the Department of Justice not to uphold the Defense of Marriage Act is a breach of his oath. … There are a number of things where a case could be made in order to impeach him, but because Republicans do not control the United States Senate, they would never allow it to get off the ground."

Even among the most conservative, anti-Obama members of Congress, supporting impeachment is a fringe position. But then, Cain isn't really competing for the median voter at this point anyway.